How can you tell the onion is a plant cell?

Question

Onions have boxy-cells, with curved sides and they are all connected. Is it possible that you can tell it's a plant cell because other cells aren't connected and aren't .. boxy?

Answer 1

Plant cells are quite different from the cells of the other eukaryotic kingdoms' organisms.

Their distinctive features are:

A large central vacuole (enclosed by a membrane, the tonoplast), which maintains the cell's turgor and controls movement of molecules between the cytosol and sap.


A cell wall made up of cellulose and protein, and in many cases lignin, and deposited by the protoplast on the outside of the cell membrane.

This contrasts with the cell walls of fungi, which are made of chitin, and prokaryotes, which are made of peptidoglycan.
The plasmodesmata, linking pores in the cell wall that allow each plant cell to communicate with other adjacent cells.

This is different from the network of hyphae used by fungi.
Plastids, especially chloroplasts that contain chlorophyll, the pigment that gives plants their green color and allows them to perform photosynthesis.
Plant groups without flagella (including conifers and flowering plants) also lack centrioles that are present in animal cells.


Kindly click on the link below for the relevent pictures-----

http://images.google.co.in/images?hl=en&q=Onion+cells&btnG=Search+Images&gbv=2

Answer 2

The onion is part of a plant, more like a bulb (the storage part) that you can plant in the soil, roots downwards. If you leave it for long enough, with light and water, it will produce leaves and eventually it will flower. This is the whole plant. Plants are made up of many thousands of cells and what's great about onions is that you can gently peel the bulb part (the bit you can eat) which is made up of layers; the very 'silky' looking thin layer is just one cell thick. If you look at these cells under a microscope, you can see all the brick-like cells each with its own nucleus and all the other bits that plant cells contain e.g. starch (not chloroplasts though, as these cells are not green and don't photosynthesise). I hope this helps.

Answer 3

There are three clues that the onion is a plant cell if you are looking at a piece of onion epidermis.

1. The cells are shaped like bricks.
2. The cell wall looks a little thicker than the plasma membrane which is just inside the cell wall. Note: if you add a little salt water, the plasma membrane will pull away from the cell wall and you will be able to see it as a separate layer.
3. There is a central vacuole which makes the inner part of the cell look a little vacant -- not entirely vacant because there is more cytoplasm above and below the vacuole, but it does look a bit clearer in the center.

If you are looking at a part of the shoot system (the green part) then you will see chloroplasts, but you won't see these in the onion's bulb part.

Answer 4

You can tell that onion cells are plant cells by looking at them under the microscope. You can see that they have a nucleus (a darker dot) and a cell wall (giving it a boxy shape).

The presence of a nucleus shows that it is either a plant cell or an animal cell, as only these kinds of cells have nuclei. The presence of a cell wall shows that it is either a plant cell or a bacterial cell, as only these kinds of cells have walls. The presence of both of these features show that it is a plant cell, as only plant cells have both of these features.